The Analytical Chemistry Facility Core is composed of a Mass Spectrometry Laboratory and a Metals Analysis Laboratory. The Metal Analysis lab was added to the facility prior to the last NIEHS Center grant renewal in 1995. The Mass Spectrometry (MS) laboratory provides analytical methods and data to determine chemical structure and to identify components in chemical mixtures. Both low and high resolution MS instruments are employed with a variety of sample introduction techniques (e.g. gas chromatography and mass spectrometry, fast atom bombardment, and direct probe) and ionization methods (electron impact and chemical ionization). The Atomic Absorption (AA) laboratory provides analyses of metals in a variety of matrices. A sample preparation laboratory contains two HPLC systems. The director of the laboratory has experience with NMR techniques and has arranged to provide NMR analyses and data interpretation. The list of services provided to the Center indicates that MS and AA analyses predominate.